Saccharomyces cerevisiae biosorbed with grape pomace flavonoids: adsorption studies and in vitro simulated gastrointestinal digestion

The residual Saccharomyces cerevisiae from brewing was used as a biosorbent of flavonoids of hydro alcoholic extract from samples of grape pomace (Merlot and Tannat). Biosorption assays verified that the pseudo-second order kinetic model and the Dubinin-Raduschkevich isotherm model presented the best fit, with free energy of adsorption (E) of 7.1 and 6.5 kJ for the Merlot and Tannat varieties, respectively, indicating that the yeast has many binding sites and adsorption was a physical process. The analysis of microscopy and spectroscopy showed differences in structure and composition of the yeast after biosorption, demonstrating that the application was effective, which was confirmed by the chromatographic analysis, where a reduction in 17% and 50% in the catechin peak was observed in the Merlot and Tannat samples, respectively. Finally, there was an increase in the in vitro bioaccessibility of flavonoids in 68% for the Merlot sample and 88% for Tannat, reaching the main objective of this application.     

红曲黄色素和红曲橙色素的稳定性研究

为了研究不同色素组分的稳定性差异,利用大孔树脂柱层析分离得到了黄色组分Fl和橙色组分F2,其中Fl主要含有红曲素(monascin)和安卡红曲黄素(ankaflavin),F2主要含有红曲玉红素(monascorubrin)和红斑红曲素(rubropunctatin).以Fl和F2为材料,从光谱特征及色素残留率等方面分...     

黑索今炸药在超临界二氧化碳中溶解特性的实验研究

用紫外分光光度计测定了温度为303,308,313,323 K,压力为7~20 MPa条件下,黑索今炸药(RDX)在超临界二氧化碳中的溶解度,并建立了波长为255 nm时RDX/乙腈溶液的浓度-吸光度关系。结果表明,在低压条件下(7~15 MPa)黑索今炸药在超临界二氧化碳中的溶解度随着温度的升高略有降低;但随着压力增大,溶解度随温度的升高而增大。对这一实验结果进行了理论分析。从整个测试结果看,RDX在超临界二氧化碳中的溶解度非常低,每克二氧化碳中最多能溶解10-5克量级的RDX。     

纳米Mo-ZSM-5分子筛的合成与表征

采用原位水热合成法,在SiO2- MoO3-TPAOH-Na2O-H2O体系中成功合成了纳米Mo-ZSM-5分子筛,并通过TEM、粉末X射线衍射(XRD) 、红外光谱( FT-IR)、紫外可见漫反射(UV-Vis)和紫外拉曼光谱(UV-Ramam)手段对其进行了表征。结果表明,该分子筛粒径约10~30nm,粒度分布均匀。随着Mo含量的增加,纳米Mo-ZSM-5样品的晶胞参数随之增大。此外,FT-IR谱在968cm -1 出现弱吸收峰、UV-Ramam谱在967 cm-1出现吸收峰,并且其强度随着Mo原子含量的增加而增强,充分证明Mo原子进入了纳米Mo-ZSM-5分子筛骨架。     

有机半导体Butyl-PBD的DFT理论计算研究

采用密度泛函理论(DFT)方法对2-(4-叔丁苯基)-5-(4-联苯基)-1,3,4-恶二唑(Butyl-PBD)进行了B3LYP/6-31G水平上的分子结构优化、红外光谱、Raman光谱、紫外-可见光谱、分子前线轨道、分子电子密度、Mulliken电荷等理论计算.研究结果表明:理论计算结果与实验数据吻合得较好,对IR、THz、UV-Vis吸收光谱和Raman散射光谱中的特征峰进行了归属,发现Butyl-PBD在0.1～10 THz波谱范围内有五个明显的吸收峰,分别位于2.04THz、3.48THz、5.16THz、6.60THz及7.08THz,Butyl-PBD在紫外光波段有三个吸收波段,分别对应于326.76nm、279.60nm及269.31 nm,其中326.76nm的紫外吸收峰最强.电子密度计算表明,最大电子密度集中在O原子上,N原子的电子密度次之.Mulliken电荷计算表明,负电荷主要集中在O原子和N原子上,所有H原子的Mulliken电荷都为正电荷,C原子的Mulliken电荷则与其具体位置相关.     

主成分分析联合Fisher判别在紫外-可见光谱法水质检测中的应用

水质类型的判别是实现光谱法水质参数准确检测的重要前提。针对直接光谱法水质检测系统采集的光谱数据信息冗余较大的问题, 利用主成分分析消除信息指标间的相关性,实现光谱数据的降维和特征信息提取。采集某化工厂和某溪水水样的紫外-可见光谱数据, 利用主成分分析联合Fisher判别的方法建立判别模型,以12组水样光谱数据作为训练样本,6组作为测试样本,对模型的判别能力进行论证和检验,并与传统的Fisher判别模型进行对比实验。实验结果表明,利用主成分分析联合Fisher判别模型可以有效消除信息冗余带来的影响,相比传统的Fisher判别模型具有分类精度高、回代误判率为零、计算时间短等优点,计算时间由传统Fisher判别方法的0.6733 s减少到0.6012 s。该方法为直接光谱法水质类型判别工程实用化提供了一种高效手段。     

“芘”核化合物合成与单/双光子性能

本文合成了四个"芘"核化合物并进行了结构验证,同时本文还研究了不同"枝"及"枝"数的不同对"芘"核化合物的单、双光子荧光性质的影响。实验结果表明,随着"枝"数增加,共轭度的增加,所得化合物的单、双光子荧光强度明显增强。而在共轭度相同的条件下(共轭度:P-T1=P-B1,P-T3=P-B3),三苯胺结构的扭曲运动消耗了能量,以热的形式释放,使得三苯胺枝化合物的单光子荧光强度明显减弱。     

Effect of N and C ion beam bombardment on the optical and structural characteristics of ethylene-norbornene copolymer (TOPAS)

Ion bombardment is a suitable tool to modify the optical properties of polymers. In the present study the effect of ion bombardment on the optical absorption of ethylene-norbornene copolymer (TOPAS) was studied using ultraviolet-visible (UV-Vis) and Raman spectroscopy. Polymer samples were bombarded with 60 keV C⁴⁺ and N⁴⁺ ion beams to various fluences ranging from 1.0 × 10¹³ to 1.0 × 10¹⁶ cm⁻². The indirect and direct band gaps have been determined. The values of direct band gaps have been found to be greater than the corresponding values of the indirect band gaps. Activation energy has been investigated as the function of ion fluences. The number of carbon atoms per conjugated length is determined according to modified Tauc’s equation. The correlation between the optical band gap, activation energy for optical transition and the number of carbon atoms per conjugated length as well as chemical structure changes induced by ion beams irradiation have been discussed in the case of ethylene-norbornene copolymer.     

Physical and chemical response of 145 MeV Ne ion irradiated polymethylmethacrylate (PMMA) polymer

Characterization of ion induced modifications in the physical, chemical and structural properties of polymethylmethacrylate (PMMA) polymer induced by 145 MeV Ne⁶⁺ ions has been carried out by FTIR, UV-Visible, Differential scanning calorimetry (DSC) and X-ray diffraction. Heavy ion irradiation was carried out under a vacuum of ∼10⁻⁶ torr at Variable Energy Cyclotron Centre, Kolkata, India using a low beam current (∼15 nA). Ion fluences of 10¹⁰, 10¹¹, 10¹², 10¹³ ions/cm² were used. The optical band gap (E_g), calculated from the absorption edge of the UV-Vis spectra of these films in 200-800 nm region varied from 2.167 eV to 1.512 eV for virgin and irradiated samples. In FTIR spectra appreciable changes have been observed after irradiation, indicating the molecular fragmentation, cross-linking, formation of unsaturated groups and free radicals. DSC thermograms give information about the thermal stability and type of thermal reactions (exothermic/endothermic) on the application of heat to the polymer. XRD analyses show slight shift of peak position and significant changes in peak intensity. XRD results show a decrease of ∼4.12% in crystallite size of irradiated sample at the higher fluence of 10¹² ions/cm².     

The pitfalls of protein quantification in wastewater treatment studies

Proteins, as one of the principal components of organic matter in wastewater, require adequate quantification to determine their concentration in the different stages of wastewater treatment process. Recent studies have used the corrected Lowry Method for protein quantification arguing that this method can differentiate proteins from interfering humic substances. In this study, the classic Lowry Method, the corrected Lowry Method and a commercial assay kit were assessed for the protein quantification in the presence of humic acid.